Abstract: In a number of experimental situations, single polymer molecules can besuspended in a vacuum. Here collisions between such molecules are considered.The limit of high collision velocity is investigated numerically for a varietyof conditions. The distribution of contact times, scattering angles, and finalvelocities are analyzed. In this limit, self avoiding chains are found tobecome highly stretched as they collide with each other, and have adistribution of scattering times that depends on the scattering angle. Thevelocity of the molecules after the collisions is similar to predictions of amodel assuming thermal equilibration of molecules during the collision. Themost important difference is a significant subset of molecules thatinelastically scatter but do not substantially change direction.